using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace Calculator
{

	public class Calculator : System.Windows.Forms.Form
	{
		//globals
		decimal result1 = 0;
		decimal result2 = 0;
		decimal result3 = 0;
		string op = "";
		

		private System.Windows.Forms.TextBox screen;
		private System.Windows.Forms.Button button1;
		private System.Windows.Forms.Button button2;
		private System.Windows.Forms.Button butplus;
		private System.Windows.Forms.Button butequals;
		private System.Windows.Forms.Button butclear;
		private System.Windows.Forms.Button button3;
		private System.Windows.Forms.Button button4;
		private System.Windows.Forms.Button button5;
		private System.Windows.Forms.Button button6;
		private System.Windows.Forms.Button button7;
		private System.Windows.Forms.Button button8;
		private System.Windows.Forms.Button button9;
		private System.Windows.Forms.Button button0;
		private System.Windows.Forms.Button butminus;
		private System.Windows.Forms.Button butdivide;
		private System.Windows.Forms.Button butmulti;
		private System.Windows.Forms.Button butsigned;
		private System.Windows.Forms.Button butdecimal;

		private System.ComponentModel.Container components = null;

		public Calculator()
		{
			InitializeComponent();
		}

		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code

		private void InitializeComponent()
		{
			System.Resources.ResourceManager resources = new System.Resources.ResourceManager(typeof(Calculator));
			this.screen = new System.Windows.Forms.TextBox();
			this.button1 = new System.Windows.Forms.Button();
			this.button2 = new System.Windows.Forms.Button();
			this.butplus = new System.Windows.Forms.Button();
			this.butequals = new System.Windows.Forms.Button();
			this.butclear = new System.Windows.Forms.Button();
			this.button3 = new System.Windows.Forms.Button();
			this.button4 = new System.Windows.Forms.Button();
			this.button5 = new System.Windows.Forms.Button();
			this.button6 = new System.Windows.Forms.Button();
			this.button7 = new System.Windows.Forms.Button();
			this.button8 = new System.Windows.Forms.Button();
			this.button9 = new System.Windows.Forms.Button();
			this.button0 = new System.Windows.Forms.Button();
			this.butminus = new System.Windows.Forms.Button();
			this.butdivide = new System.Windows.Forms.Button();
			this.butmulti = new System.Windows.Forms.Button();
			this.butsigned = new System.Windows.Forms.Button();
			this.butdecimal = new System.Windows.Forms.Button();
			this.SuspendLayout();
			// 
			// screen
			// 
			this.screen.BackColor = System.Drawing.SystemColors.HighlightText;
			this.screen.Font = new System.Drawing.Font("Microsoft Sans Serif", 14.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.screen.Location = new System.Drawing.Point(24, 24);
			this.screen.MaxLength = 30;
			this.screen.Name = "screen";
			this.screen.ReadOnly = true;
			this.screen.RightToLeft = System.Windows.Forms.RightToLeft.Yes;
			this.screen.Size = new System.Drawing.Size(312, 29);
			this.screen.TabIndex = 0;
			this.screen.Text = "0";
			// 
			// button1
			// 
			this.button1.BackColor = System.Drawing.Color.Black;
			this.button1.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button1.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button1.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button1.Location = new System.Drawing.Point(196, 92);
			this.button1.Name = "button1";
			this.button1.Size = new System.Drawing.Size(32, 32);
			this.button1.TabIndex = 1;
			this.button1.Text = "1";
			this.button1.Click += new System.EventHandler(this.button1_Click);
			// 
			// button2
			// 
			this.button2.BackColor = System.Drawing.Color.Black;
			this.button2.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button2.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button2.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button2.Location = new System.Drawing.Point(232, 92);
			this.button2.Name = "button2";
			this.button2.Size = new System.Drawing.Size(32, 32);
			this.button2.TabIndex = 2;
			this.button2.Text = "2";
			this.button2.Click += new System.EventHandler(this.button2_Click);
			// 
			// butplus
			// 
			this.butplus.BackColor = System.Drawing.Color.Black;
			this.butplus.Cursor = System.Windows.Forms.Cursors.Hand;
			this.butplus.Font = new System.Drawing.Font("Comic Sans MS", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.butplus.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.butplus.Location = new System.Drawing.Point(304, 92);
			this.butplus.Name = "butplus";
			this.butplus.Size = new System.Drawing.Size(32, 32);
			this.butplus.TabIndex = 3;
			this.butplus.Text = "+";
			this.butplus.Click += new System.EventHandler(this.butplus_Click);
			// 
			// butequals
			// 
			this.butequals.BackColor = System.Drawing.Color.Black;
			this.butequals.Cursor = System.Windows.Forms.Cursors.Hand;
			this.butequals.Font = new System.Drawing.Font("Comic Sans MS", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.butequals.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.butequals.Location = new System.Drawing.Point(160, 92);
			this.butequals.Name = "butequals";
			this.butequals.Size = new System.Drawing.Size(32, 32);
			this.butequals.TabIndex = 4;
			this.butequals.Text = "=";
			this.butequals.Click += new System.EventHandler(this.butequals_Click);
			// 
			// butclear
			// 
			this.butclear.BackColor = System.Drawing.Color.Brown;
			this.butclear.Font = new System.Drawing.Font("Microsoft Sans Serif", 15.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.butclear.Location = new System.Drawing.Point(48, 84);
			this.butclear.Name = "butclear";
			this.butclear.Size = new System.Drawing.Size(75, 28);
			this.butclear.TabIndex = 5;
			this.butclear.Text = "Clear";
			this.butclear.Click += new System.EventHandler(this.butclear_Click);
			// 
			// button3
			// 
			this.button3.BackColor = System.Drawing.Color.Black;
			this.button3.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button3.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button3.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button3.Location = new System.Drawing.Point(268, 92);
			this.button3.Name = "button3";
			this.button3.Size = new System.Drawing.Size(32, 32);
			this.button3.TabIndex = 6;
			this.button3.Text = "3";
			this.button3.Click += new System.EventHandler(this.button3_Click);
			// 
			// button4
			// 
			this.button4.BackColor = System.Drawing.Color.Black;
			this.button4.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button4.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button4.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button4.Location = new System.Drawing.Point(196, 128);
			this.button4.Name = "button4";
			this.button4.Size = new System.Drawing.Size(32, 32);
			this.button4.TabIndex = 7;
			this.button4.Text = "4";
			this.button4.Click += new System.EventHandler(this.button4_Click);
			// 
			// button5
			// 
			this.button5.BackColor = System.Drawing.Color.Black;
			this.button5.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button5.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button5.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button5.Location = new System.Drawing.Point(232, 128);
			this.button5.Name = "button5";
			this.button5.Size = new System.Drawing.Size(32, 32);
			this.button5.TabIndex = 8;
			this.button5.Text = "5";
			this.button5.Click += new System.EventHandler(this.button5_Click);
			// 
			// button6
			// 
			this.button6.BackColor = System.Drawing.Color.Black;
			this.button6.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button6.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button6.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button6.Location = new System.Drawing.Point(268, 128);
			this.button6.Name = "button6";
			this.button6.Size = new System.Drawing.Size(32, 32);
			this.button6.TabIndex = 9;
			this.button6.Text = "6";
			this.button6.Click += new System.EventHandler(this.button6_Click);
			// 
			// button7
			// 
			this.button7.BackColor = System.Drawing.Color.Black;
			this.button7.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button7.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button7.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button7.Location = new System.Drawing.Point(196, 164);
			this.button7.Name = "button7";
			this.button7.Size = new System.Drawing.Size(32, 32);
			this.button7.TabIndex = 10;
			this.button7.Text = "7";
			this.button7.Click += new System.EventHandler(this.button7_Click);
			// 
			// button8
			// 
			this.button8.BackColor = System.Drawing.Color.Black;
			this.button8.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button8.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button8.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button8.Location = new System.Drawing.Point(232, 164);
			this.button8.Name = "button8";
			this.button8.Size = new System.Drawing.Size(32, 32);
			this.button8.TabIndex = 11;
			this.button8.Text = "8";
			this.button8.Click += new System.EventHandler(this.button8_Click);
			// 
			// button9
			// 
			this.button9.BackColor = System.Drawing.Color.Black;
			this.button9.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button9.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button9.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button9.Location = new System.Drawing.Point(268, 164);
			this.button9.Name = "button9";
			this.button9.Size = new System.Drawing.Size(32, 32);
			this.button9.TabIndex = 12;
			this.button9.Text = "9";
			this.button9.Click += new System.EventHandler(this.button9_Click);
			// 
			// button0
			// 
			this.button0.BackColor = System.Drawing.Color.Black;
			this.button0.Cursor = System.Windows.Forms.Cursors.Hand;
			this.button0.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.button0.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.button0.Location = new System.Drawing.Point(196, 200);
			this.button0.Name = "button0";
			this.button0.Size = new System.Drawing.Size(32, 32);
			this.button0.TabIndex = 13;
			this.button0.Text = "0";
			this.button0.Click += new System.EventHandler(this.button0_Click);
			// 
			// butminus
			// 
			this.butminus.BackColor = System.Drawing.Color.Black;
			this.butminus.Cursor = System.Windows.Forms.Cursors.Hand;
			this.butminus.Font = new System.Drawing.Font("Comic Sans MS", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.butminus.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.butminus.Location = new System.Drawing.Point(304, 128);
			this.butminus.Name = "butminus";
			this.butminus.Size = new System.Drawing.Size(32, 32);
			this.butminus.TabIndex = 14;
			this.butminus.Text = "-";
			this.butminus.Click += new System.EventHandler(this.butminus_Click);
			// 
			// butdivide
			// 
			this.butdivide.BackColor = System.Drawing.Color.Black;
			this.butdivide.Cursor = System.Windows.Forms.Cursors.Hand;
			this.butdivide.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.butdivide.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.butdivide.Location = new System.Drawing.Point(304, 164);
			this.butdivide.Name = "butdivide";
			this.butdivide.Size = new System.Drawing.Size(32, 32);
			this.butdivide.TabIndex = 15;
			this.butdivide.Text = "/";
			this.butdivide.Click += new System.EventHandler(this.butdivide_Click);
			// 
			// butmulti
			// 
			this.butmulti.BackColor = System.Drawing.Color.Black;
			this.butmulti.Cursor = System.Windows.Forms.Cursors.Hand;
			this.butmulti.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.butmulti.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.butmulti.Location = new System.Drawing.Point(304, 200);
			this.butmulti.Name = "butmulti";
			this.butmulti.Size = new System.Drawing.Size(32, 32);
			this.butmulti.TabIndex = 16;
			this.butmulti.Text = "x";
			this.butmulti.Click += new System.EventHandler(this.butmulti_Click);
			// 
			// butsigned
			// 
			this.butsigned.BackColor = System.Drawing.Color.Black;
			this.butsigned.Cursor = System.Windows.Forms.Cursors.Hand;
			this.butsigned.Font = new System.Drawing.Font("Comic Sans MS", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.butsigned.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.butsigned.Location = new System.Drawing.Point(268, 200);
			this.butsigned.Name = "butsigned";
			this.butsigned.Size = new System.Drawing.Size(32, 32);
			this.butsigned.TabIndex = 17;
			this.butsigned.Text = "+/-";
			this.butsigned.Click += new System.EventHandler(this.butsigned_Click);
			// 
			// butdecimal
			// 
			this.butdecimal.BackColor = System.Drawing.Color.Black;
			this.butdecimal.Cursor = System.Windows.Forms.Cursors.Hand;
			this.butdecimal.Font = new System.Drawing.Font("Comic Sans MS", 15.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.butdecimal.ForeColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.butdecimal.Location = new System.Drawing.Point(232, 200);
			this.butdecimal.Name = "butdecimal";
			this.butdecimal.Size = new System.Drawing.Size(32, 32);
			this.butdecimal.TabIndex = 18;
			this.butdecimal.Text = ".";
			this.butdecimal.Click += new System.EventHandler(this.butdecimal_Click);
			// 
			// Calculator
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.BackColor = System.Drawing.Color.Silver;
			this.ClientSize = new System.Drawing.Size(360, 406);
			this.Controls.Add(this.butdecimal);
			this.Controls.Add(this.butsigned);
			this.Controls.Add(this.butmulti);
			this.Controls.Add(this.butdivide);
			this.Controls.Add(this.butminus);
			this.Controls.Add(this.button0);
			this.Controls.Add(this.button9);
			this.Controls.Add(this.button8);
			this.Controls.Add(this.button7);
			this.Controls.Add(this.button6);
			this.Controls.Add(this.button5);
			this.Controls.Add(this.button4);
			this.Controls.Add(this.button3);
			this.Controls.Add(this.butclear);
			this.Controls.Add(this.butequals);
			this.Controls.Add(this.butplus);
			this.Controls.Add(this.button2);
			this.Controls.Add(this.button1);
			this.Controls.Add(this.screen);
			this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
			this.Name = "Calculator";
			this.Text = "The Bruce Calculator";
			this.ResumeLayout(false);

		}
		#endregion


		[STAThread]
		static void Main() 
		{
			Application.Run(new Calculator());
		}

		private void button1_Click(object sender, System.EventArgs e)
		{
			if(screen.Text == "0")
			{
				this.screen.Text = "1";
			}
			else
			{
				screen.AppendText("1");
			}


			}

		private void button2_Click(object sender, System.EventArgs e)
		{
			if(screen.Text == "0")
			{
				this.screen.Text = "2";
			}
			else
			{
				screen.AppendText("2");
			}
		}



		private void button3_Click(object sender, System.EventArgs e)
		{
		
		}

		private void button4_Click(object sender, System.EventArgs e)
		{
		
		}

		private void button5_Click(object sender, System.EventArgs e)
		{
			if(screen.Text == "0")
			{
				this.screen.Text = "5";
			}
			else
			{
				screen.AppendText("5");
			}
		}

		private void button6_Click(object sender, System.EventArgs e)
		{
		
		}

		private void button7_Click(object sender, System.EventArgs e)
		{
		
		}

		private void button8_Click(object sender, System.EventArgs e)
		{
		
		}

		private void button9_Click(object sender, System.EventArgs e)
		{
		
		}

		private void button0_Click(object sender, System.EventArgs e)
		{
		
		}

		private void butclear_Click(object sender, System.EventArgs e)
		{
			screen.Text = "0";
			result1 = 0;
			result2 = 0;
			result3 = 0;
		}

		private void butplus_Click(object sender, System.EventArgs e)
		{	
			op = "+";
			if(result1 == 0)
			{
				result1 = decimal.Parse(screen.Text);
				screen.Text = "";
			}
			else
			{
				result1 = result1 + decimal.Parse(screen.Text);
				screen.Text = "";
			}
			

		}

		private void butequals_Click(object sender, System.EventArgs e)
		{
			result2 = decimal.Parse(screen.Text);
			switch(op)
			{
				case "+":
					arithmetic temp = new arithmetic();
					result3 = temp.add(result1, result2);
					result1 = result3;
					screen.Text = result1.ToString();
					result3 = 0;
					
					break;

				case "-":
					arithmetic temp1 = new arithmetic();
					result3 = temp1.minus(result1, result2);
					result1 = result3;
					screen.Text = result1.ToString();
					result3 = 0;
					break;

				case "/":
					arithmetic temp2 = new arithmetic();
					result3 = temp2.divide(result1, result2);
					result1 = result3;
					screen.Text = result1.ToString();
					result3 = 0;
					break;

				case "*":
					arithmetic temp3 = new arithmetic();
					result3 = temp3.multi(result1, result2);
					result1 = result3;
					screen.Text = result1.ToString();
					result3 = 0;
					break;
			}
			
		}

		private void butminus_Click(object sender, System.EventArgs e)
		{
			op = "-";
			if(result1 == 0)
			{
				result1 = decimal.Parse(screen.Text);
				screen.Text = "";
			}
			else
			{
				result1 = result1 - decimal.Parse(screen.Text);
				screen.Text = "";
			}
		}

		private void butdivide_Click(object sender, System.EventArgs e)
		{
			op = "/";
			if(result1 == 0)
			{
				result1 = decimal.Parse(screen.Text);
				screen.Text = "";
			}
			else
			{
				result1 = result1 / decimal.Parse(screen.Text);
				screen.Text = "";
			}
		}

		private void butmulti_Click(object sender, System.EventArgs e)
		{
			op = "*";
			if(result1 == 0)
			{
				result1 = decimal.Parse(screen.Text);
				screen.Text = "";
			}
			else
			{
				result1 = result1 * decimal.Parse(screen.Text);
				screen.Text = "";
			}
		}

		private void butdecimal_Click(object sender, System.EventArgs e)
		{
		
		}

		private void butsigned_Click(object sender, System.EventArgs e)
		{
		
		}


	}
}


///////////////class in another file

using System;

namespace Calculator
{
	
	public class arithmetic
	{
		public arithmetic()
		{
			//
			// TODO: Add constructor logic here
			//
		}

		public decimal add(decimal a, decimal b)
		{
			return a + b;
		}

		public decimal minus(decimal a, decimal b)
		{
			return a - b;
		}

		public decimal divide(decimal a, decimal b)
		{
			return a / b;
		}

		public decimal multi(decimal a, decimal b)
		{
			return a * b;
		}


	}
}